He told a conference on money laundering organized by the American Bankers Association that the Obama administration is still following a two-track strategy of talking to Tehran but is "working intensively" on plans for broader sanctions if Iran does not allay fears it is working on nuclear weapons.
"In the event that Iran's actions make it necessary to implement this plan, it seems quite likely that we will turn to you to help ensure the effective implementation of any financial, investment or trade-related measures that are imposed," he said.
A week ago, another senior Treasury official similarly warned that the United States was prepared to raise the stakes for Tehran. Iran played down the threat, saying that previous U.S. sanctions had been ineffective because other countries recognized the benefits of trading with the oil-rich nation.
Stuart Levey, under secretary for the U.S. Treasury's Office of Terrorism and Financial Intelligence, told Congress last week that other countries' help would be sought in implementing any new measures.
"It (the U.S. strategy) takes into account that no single sanction is a 'silver bullet' — we will need to impose measures simultaneously in many different forms to be effective," Levey told lawmakers at a Capitol Hill hearing.
Cohen said that targeted financial measures, used alongside other national security and law enforcement tools, have disrupted terrorist financing networks for many organizations including al Qaeda.
He said some terror organizations now were turning to criminal activity to raise money and said that gave authorities a chance to disrupt their activities by using the banking industry's systems to detect movements of large sums of money.
"Although the suspicious transactions … may be several steps removed from a terrorist act, the information you provide is analyzed to protect against international terrorism," Cohen told the bankers.
(Reporting by Glenn Somerville; Editing by Eric Walsh)
